The present invention relates to a semiconductor circuit and, more particularly, to a semiconductor circuit having a redundancy function.
FIG. 5 shows a Y redundancy arrangement as an example of a semiconductor circuit having a conventional redundancy function.
As shown in FIG. 5, in the conventional semiconductor circuit, two redundancy switches 121 and 122 arranged between two memory banks (redundancy objects) 111 and 112 are connected to recovery lines RYSWA, RYSWB, RYSWC, and RYSWD for the memory banks 111 and 112. The redundancy switch 121 selects the recovery line RYSWA or RYSWB. The redundancy switch 122 selects the recovery line RYSWC or RYSWD.
In the semiconductor circuit having this arrangement, for example, when one defect is generated in each of the banks 111 and 112, the redundancy switch 121 selects the recovery line RYSWA, and the redundancy switch 122 selects the recovery line RYSWD. When two defects are generated in the bank 111, the redundancy switch 121 selects the recovery line RYSWA, and the redundancy switch 122 selects the recovery line RYSWC. When two defects are generated in the bank 112, the redundancy switch 121 selects the recovery line RYSWB, and the redundancy switch 122 selects the recovery line RYSWD.
In this manner, when defects are generated in the banks 111 and 112, the redundancy switches 121 and 122 select connection to the recovery lines RYSWA, RYSWB, RYSWC, and RYSWD in accordance with the defective banks. Any of the recovery lines RYSWA, RYSWB, RYSWC, and RYSWD that are connected to the redundancy switches 121 and 122 replace the defects to recover the generated defects.
In the conventional semiconductor circuit described above, since the four recovery lines for the banks are connected to the two redundancy switches arranged between the two banks, the number of redundancy switches are large, requiring a large area of the semiconductor circuit.